Plate glass surfacing table



Sept. 18, 1934. J. SODERBERG PLATE GLASS SURFAGING TABLE 4 Sheets-Sheet 1 Filed NOV. 25, 1933 IN VENT OR c/Hco 5 5 ODEEBERCE ATTORNEYS.

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PLATE GLASS SURFACING TABLE Filed Nov. 23, 1933 4 Sheets-Sheet 2 Fig. 8

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Sept? 18, 1934- J. SODERBERG 1,973,733

PLATE GLASS SURFACING TABLE Filed Nov. 23, 1953 4 Sheets-Sheet 3 INVENTOR u/RCOB (S DERBERG. I

@WJRN M Patented Sept. 18, 1934 PLATE GLASS SURFACING TABLE Jacob Soderberg, Pittsburgh, Pa., assignor to Pittsburgh Plate Glass Ccmpany, a corporation of Pennsylvania Application November 23, 1933, Serial No. 699,424

4 Claims.

The invention relates to tables for use in surfacing plate glass in which the tables are passed in a continuous train beneath a series of grinding and polishing runners. The heat developed 5 in the polishing operation causes the tops of the tables to warp or bow slightly so that they are no longer true and flat, and when returned to the grinding end of the cycle for reuse, this bowed or warped condition persists to a certain extent "so that the glass sheets are not ground to uniform thickness, the sheets being ground thinner in the portions overlying the centers of the tables than those overlying the sides of the tables. The .object of the present invention is to provide an improved table construction in which the warping of the table tops due to the heat developed in polishing is substantially eliminated. Briefly stated, this is accomplished by reducing the area of contact between the table top and its frame- 'work to a minimum and by subdividing the top so that any warping effect on the top as a whole is reduced to a minimum. Under these conditions the heat transmitted from the top to the framework is so reduced that the framework will not deform or warp perceptibly. Certain embodiments of the invention are illustrated in the accompanying drawings, wherein:

Figure 1 is a plan View of the construction. Fig. 2 is a longitudinal section on the line II--II of Fig. 1. Fig. 3 is a transverse section on the line III-III of Fig. 1. Fig. 4. is an isometric section on the line VIV of Fig. 1. Fig. 5 is an isometric section on the line VV of Fig. 1. Figs. 6 and '7 are sections on the lines VIVI and VII-VII of Fig. 1. And Figs. 8 and 9 are sections showing modifications.

Referring to the drawings, the body of the car is made up of two sections 1 and 2, having abutting flanges 3 and 4 with an interposed key 5 suitably bolted together. These sections are similar so that a description of one will be sufficient and it will be understood that the car may be made of as many sections as is desired. The car is provided on its under side with a rack 6 adapted to engage a spur gear which moves the train of cars longitudinally of the track upon which they are mounted. The car or table is provided with a plurality of wheels 7 resting upon the track 8. At each end of the car is suitable coupling mechanism 9 adapted to couple the car to adjacent cars, such as the car 10 shown at the right of Fig. 2.

The frame of the car consists of a plurality of longitudinal ribs 11, 11, etc. and a plurality of transverse ribs 12, 12, etc. which intersect and constitute an integral structure. Also integral Withthe ribs is atop in the form of the plate 13', which carries the glass sheet 1301 secured to the plate by the plaster 13b (Fig. 6), such plate being coextensive in area with the area of the frame. This plate contacts with the ribs only at their intersection, at which point the integral spacing lugs 14, 14, etc. are provided. At all other points, the tops of the ribs 11 and 12 are spaced away from the plate 13 providing the air spaces 15. The provision of the lugs 14 with the air spa 15 serves to give the top 13 a minimum amount of contact with the ribs 11 and 12, so that the heat transmission from the plate to the ribs is reduced to a minimum. The underfrarning, consisting of the ribs 11 and 12, is thus kept from heating to any substantial extent, so that during the polishing operation, there is little or no deformation of the frame.

In order to reduce the warping of the table top 13, such top is preferably divided into a large number of rectangular sections 16, 16, etc. by cutting out the grooves 17, 1'7, etc. The upper portion of these grooves is filled with strips of rubber 18 to prevent the plaster used in cementing the glass to the table top from working through the grooves. When the top is subdivided in this manner, each section 16 is independent of adjacent sections, so that while each section may warp slightly, the effect is not cumulative and the top as a whole remains substantially flat and true even though raised to a relatively high temperature during the polishing operation. Where two adjacent tables come together, the opposing ends of the top sections are grooved, as indicated in Fig. 7, and each is provided with a rubber filler strip 19. The opposing ends of the frame structure lying below the grooves carrying the strips 19, 19 come together, as indicated in Fig. '7, and are provided with the bumper strips 20, 20.

Fig. 8 illustrates a modification in which the grooves which separate the sections 16, 16 eiztend only partially through the top and are filled with the rubber strips 21, 21 which perform the function of the strips 18. While the tendency to warp with this kind of top is somewhat greater than that of the construction of Figs. 1 to 7, the grooves, even though they do not extend clear through the top, tend to reduce this warping effect.

Fig. 9 illustrates a further modification in which the top 13 is not subdivided by the grooves. This lacks the advantage of the grooved top, but in many cases, the top will remain flat without the grooving feature, incident to the frame con struction having the minimum area of contact with the top as heretofore described. It will be ces loo

2. A plate glass surfacing table comprising a.

frame consisting of a plurality of intersecting spaced longitudinal and transverse ribs with upstanding lugs at intervals along the ribs anda top integral with the frame in the form of a plate having connection with the frame atsaid lugs and at other points spaced away from the frame, said plate being divided into a plurality of rectangular sections by intersecting grooves extending longitudinally and transversely thereof intermediate said ribs so that each section is carried by'one of said lugs.

3. A plate glass surfacing table comprising a frame consisting of a plurality of intersecting spaced longitudinal lugs at intervals along the ribs and a top integral with the frame in the form of a plate having connection with the frame at said lugs and at other points spaced away from the frame, said plate being divided into a plurality of rectangularsections by intersecting grooves extendinglongitudinally and transversely thereof intermediate said ribs so that each section is carried by one of said lugs and said grooves being filled with yielding material.

4. A plate -glass:surfacing table comprising a frame consisting of a plurality of intersecting spaced longitudinal and transverse ribs with upstanding-lugs atthe-intersection of the ribs, and a top"'integral'with the frame in the form of a plate'having' connection with the frame at said lugs and at other points spaced away from the frame.-

JACOB SODERBERG. 

